Pulp-screen.



L. S. WILLIAMSON.

PULP SCREEN.

APPLICATION FILED SEPT. 16, 1909.

Patented Jan. 11,1910.

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PULP SURF-EN.

APPLICATION IILED SEPT. 16, 1909.

946, 185, Patented Jan. 11, 1910.

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' UNITED STATES PATENT OFFIQE.

LUCIUS S. WILLIAMSON, OF LOCKLAND, OHIO.

PULP-SCREEN.

To all whom it may concern:

Be it known that I, LUoIUs S. WILLIAM- SON, a citizen of the UnitedStates, residing at Lockland, in the county of Hamilton and State ofOhio, have invented certain new and useful Improvements in Pulp-Screensfor Use in Screening the Pulp in Paper-Making, of which the following isa full, clear, and exact description, reference being had to theaccompanying drawings, forming part of this specification.

My invention relates to improvements in the construction of the slottedplates used as screens in straining the pulp in the manufacture ofpaper, and the object of the invention is to provide screen plates andmeans for securing them in place, whereby the screens may be readily andeasily removed and replaced for cleaning or changes in paper stock orotherwise, and in which the necessity for the use of screws to hold theplates in place is entirely obviated. As now used these screen platesmust fit accurately into the frames and be secured so as to be watertight, and it is customary to fasten the plates in place by a largenumber of screws. Vith each change of the paper stock, and alsofrequently for cleaning, it is necessary to remove the screens from theframes. This is a long and tedious operation, and in addition the screwsand screw holes are subject to injurious wear, the screws loosen andwork out with consequent leakage, or the screws become rusted in theplace and the slotted heads damaged, and great difliculty is frequentlyexperienced in freeing the plates for removal.

My invention is designed to overcome these difficulties, and it consistsof that novel construction of a screen and the method of securing thesame, to be hereinafter pointed out and claimed, whereby each pair ofplates is locked in place by a cam lever to be released instantly, anclin which the use of screws is entirely obviated.

In the drawings Figure 1 is a perspective view of a portion of the framewith several screen plates in place and one removed. Fig. 2 is alongitudinal section of the construction shown in Fig. 1; Fig. 3 is aperspective view of one of the screen plates. Fig. 1 is a perspectiveview of a portion of the retaining frame to which the plates aresecured. Fig. 5 is a perspective View of the cam lever.

1, 2 and 3 are the sides and ends of the wooden framework or box, inwhich the Specification of Letters Patent.

Application filed September 16, 1909.

Patented Jan. 11, 1910. Serial No. 518,023.

screens for straining the pulp are located. Tl'llS box 1s also providedwith cross pieces 1, 1, separated from each other the width of one ofthe screens, the screen plates them selves usually being a foot in widthand three and one-half to four feet in length, while the box isconstructed to hold as many screens as may be desired.

5, 5 are metal screen plates provided with transverse slots 6, 6, forthe passage of the material, and with the longitudinal rib 7 forstrengthening purposes.

The plates are secured in the box as fol lows: Mounted securely withinthe wooden box along the sides and ends, and on the cross pieces 4, is ametal frame made up of end strips 8, 8 and side strips 9, 10, with crossbars 11. These strips are tenoned and mortised so as to fit tightlytogether at the ends where they are securely fastened to the frameworkby screws, a single screw at each corner, and at the ends of the crossbars being required, while at short intervals other screws are employedto rigidly secure this metal frame in place. The end bars 8 and thecross bars 11 are provided at short intervals with beveled forwardlyprojecting lugs 12, 12 and 13, 13, while one of the side strips.

9 is formed with a longitudinal undercut dove-tailed recess 14, and theopposite side strip 10 is formed with a dove-tailed recess 15. Eachscreen plate 5 is formed at one end with a corresponding dove-tailedtenon 16, to engage the recess 14;, and with a beveled surface 17 at theother end to engage the recess 15. The plates are also provided withmortises 18, 18 on the under surface along the side edges to engage thelugs 12 and 13. The transverse bars 11 are wide enough to engage a pairof the screen plates, so that when the plates are located in the boxthey will fit tightly together along the side edges. Pivoted on suitablescrew bolts 19, 19, mounted on the plates 20, secured to one of thesides of the box frame are the cam levers 21, provided with the camsurface 22, which engages in the slot 28, formed at the abutting edge ofeach pair of screen plates.

It will be evident from the foregoing description how readily and easilymy screen plates can be located in and removed from the pulp box.

The dove-tailed tenon 16 of each plate is slipped within the mortise 14and the plate pushed to its seat in the frame with the lugs 12, 13engaging the recess underneath the plate, and the plates are arranged inpairs with the recess 23 contiguous and the lever 21 being thrown overto the right, each pair of plates is rigidly and securely locked inplace, to be released as readily by turning the cam lever to the left.The cam surface on the cam levers is constructed so as to force theplates downward and away from the lever, so that the plates are rigidlylocked in place. In order to permit any sediment to run out and bereadily removed from the recess let, the portions are cut away at 2%,2st, at the ends of the strips and at the tenons of the transversestrips.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent, is:

1. In a receptacle for straining paper pulp, with metal strips securedalong the inner bottom edges, the side strips provided I withlongitudinal mortises and the transverse strips with tenons, metalscreen plates correspondingly mortised and tenoned to engage themortises and tenons of the metal. strips, with levers to lock the platesin place.

2. A receptacle for straining paper pulp, with metal strips securedalong the inner bottom edges, and with intermediate cross strips, theside strips provided with longi tudinal mortises and the transversestrips with forwardly projecting tenons, and metal screen platescorrespondingly mortised and tenoned to engage the niortiscs and tenonsof the metal strips, with cam levers to force and lock the plates inplace.

3. A receptacle for straining paper pulp, metal strips secured along theinner bottom edges, and with intermediate cross strips, one of the sidestrips provided with a longitudinal undercut dove-tailed mortise, witha, longitudinal dove-tailed recess for the opposite side strip, and thetransverse strips formed with forwardly projecting tenons, and metalscreen plates correspondingly mortised and tenoned to engage themortises and tenons of the metal strips, and with cam levers pivoted tothe sides and engaging said screen plates to force and lock them inplace, with a groove in each pair of screen plates with which the camlevers engage.

LUCIUS S. WILLIAMSON. Vitnesses lVILLIAit C. Dmronnr, MAX ADDLEMAN.

